Process and product



Patented June 29, 1943 uNlfrsosTA'rss PA ENT- OFFICE PaulBollandAustinandOlsarlea Wilmlnston,Del..a-lnors compalmwllmingtomnel.

Nemours &

poratlon oi Delaware No Drawlns. Application semmm es, 1m,

Serhl No. 297,100

12 Claims. (CL 260-399) This invention relates to organic compounds,

more, particularly to amides and specifically to thioethers ,ot' N-mercaptomethyi amides oi monobasic acids.

This invention has as an object the prepara ethyl alcohol at room is added 14 parts of ethyl mercaptan. With agitation, 30

parts of concentrated hydrochloric acid is slowly added to the mixture. The resultant solution is tion of. thioethers of N-mercaptomethyl amides oi monobasic acids. A iurther object is the pro- .vision oi as process for the preparation of these amides. A further object is the preparation of new compounds of use as pesticides. rubber chemicals, and petroleum chemicals. Other obiects will appear hereinafter.

These objects are accomplished by the followin: invention wherein amethylol amide of an aliphatic monobasic acid havin: a monovalent orsanic radical oi at least'three carbon atoms attached throuzhvcarbon to the carboxyl group is reacted with an aliphatic mercaptan to form an aliphatic thioether oi the N-mercaptomethyl amide oi the monobasic acid. In the preierred practice of this invention, an acid catalyst is used, the reaction is carried out'at room temperature, and a suitable solvent is employed.

A 'methylol amide or methyloi lactam, such as methylol lauramide, and a merca'ptan, such as v ethyl mercaptan. in approximately eq lmolar amounts are dissolved or suspended in asuitable solvent. such as ethyl alcohol. A mixture oi the amide or lactam .and formaldehyde (or mmaldehyde generating aaent) may be substituted by iorminz'the' methylol compound asan intermediateinthereacflonmixture. Anacid,sueh as hydrochloric acid, is-sdded to catalyse the reaction. and the mixtureor solution islet stand 12-16 hours at room temperature, or

cipitated product is removed by nitration, washed for the methylolamide or methylol lactam, thereheatedtocompletethereaction inashorter time. 'The'reaetlonmixtureispoured into severalvoiumesoiwatertoprecipitatethereaction product. It eatalyst'may be neutralized by addinato thewater an alkaline reagent such as soditml carbonate. The crude productmaybepuriiledby a suitable solvent such as ethyl alcohol, or,-in

eertalncaseahydistillatiom The more detailed pradtig'aioi' the invention is illustrated hythe iollowinl qexamples. wherein partssivenarehywelahb: 'Ihereareoieourse many terms 0! the invention other than speeiiic embodiment.

.. usw l. Toupartsotmethyiollauramldepartlydissolved andpartly suspendedin 240 partaoiss crystallization from.

' in 11.73. "I. 8

let stand 16-20 hours, then poured into 1000 parts of ice water. The precipitated product a removed by filtration. washed several times with water and air dried. A theoretical yield (44 parts) .01 crude N-(ethylthiomethyl) Jam-amide melting at 59-60 .C. is obtained. After several crystalliaations from 19% alcohol, the product melts at 62-63. Thesuliur content is 11.00, the'theoretical sulfur content for CuHnNOB be- To a cold mixture of 41 partsoimethylol caprylamide, lt'partsof ethyl mercaptan and 160 parts oi ethyl aIcohoL'there is slowly added 48 parts of concentrated hydrochloric acid. The resultant solution is let stand three days and then pouredinto400partsoieoldwater. Theprewith-cold water and air dried. A061 yield (40 parts) of crude N-(l) -caprylamide is obtained. Alter several crystallisations [methyl alcohol, the product melts at 37-08" C. The sulfur content is 14.00, the theoretical suliur content for climates heina 14.15.

"1.74. the theoretical suliur content ior CuHoNOB being 8.00.

ethyl mercaptan and allowed to stand 12-16 hours. The reaction mixture is poured into 500 parts of 5% sodium hydroxide solution, the oily layer drawn. off, washed with 100 parts of alkali and 100 parts of water, the formation of a layer being facilitated by'the addition of 100 parts of ether. The extract is dried with anhydrous sodium sulfate. Distillation produces 122 parts of N-(ethylthiomethyl) -caprolactam, a clear liquid boiling at 138-41" 'C./5- 6 mm. (65% yield). The sulfur content is 17.30, the theoretical sulfur content for CsHrzNOS being 17.12.

Example V A mixture of 1.7 parts lauramide, 1.5 parts paraformaldehyde, 1.3 parts ethyl mercaptan, 1.2 parts concentrated hydrochloric acid, and parts ethyl alcohol is warmed a few minutes on a steam bath under reflux. The resultant solution is let stand several hours at room temperature, then poured into 500 parts of water. The precipitated product is removed by filtration, washed with water and air dried. An 80% yield (1.6 parts) of crude N-(ethylthiomethyl) -lauramide is obtained. Upon recrystallization the product melts at 62-63 C.

This invention is generic to the reaction of methylol amides of aliphatic monocarboxylic acids of at least four carbon atoms, including butyric acid, isobutyric acid, the isomeric valeric, caproic and capric acids, palmitic acid, stearic acid, lauric acid, linoleic acid, oleic acid, linolenic acid, mixtures of these acids derived from natural or hydrogenated fats or oils, undecyileni'c acid, methacrylic acid, and crotonic acid. It is also applicable to N-methylol derivatives of cyclic amides (lactams) such as N-methylol butyrolactam, -N-methylol-gamma-valerolactam, N-methylol delta valerolactam, N-methylol-wcaprolactam, etc.

Any aliphatic mercaptan may be' used including methyl, ethyl, propyl, amyl, and butyl mercaptans, and mixed isomeric amyl mercaptans derived from mixed amyl chlorides, dodlecyi, hexadecyl, and octadecyl mercaptans, and dimercaptans, such as ethylene and hexamethylene dimercaptans. The alkyl mercaptans are preferred,

The invention may be operated over a wide temperature range, depending on the reactivities of. individual components of the reaction mixture and the solvent employed. In general, with the more active compounds, reaction is practically complete within a few hours at room temperature, in some. cases within a few minutes. With less active compounds, especially when operating without a catalyst, condensation is. effected by heating at temperatures between 30 and 150 C. and preferably between 100 C. It is often convenient to carry out the reaction at the boiling point of the solvent or one of the reactants used.

The methylol compound may be previously isolated and used as such, or it may be formed in the reaction solution from the amide (or lactam) and formaldehyde or a formaldehyde generating agent. The formaldehyde may be added as a gas, as a solution, or as a solid (paraformaldehyde or polyoxymethylene glycols). Among other formaldehyde sources are formals such as methylal, cyclic formaldehyde derivatives such as s-trioxane, and the various formaldehyde polymers known as alpha-, beta-, gamma-, delta-, epsilon-polyoxymethylenes.

The reaction is generallycarried out using approximately equimolar amounts of the reactants, but an excess of one of the reagents may be employed to insure complete reaction. The order of addition of the reacants to the reaction mixture may be varied. Usually the acid cat-,

alyst is added to a solution of the methylol compound and the mercaptan, the methylol compound having been formed or placed in solution before adding the mercaptan. However, the amide or lactam, formaldehyde, mercaptan and catalyst may be placed in solution simultaneously and these components interacted in one step.

Alternatively, the mercaptal or hemimercaptal may be formed first and subsequently reacted with the amide.

Solvents such as alcohols, ethers and hydrocarbons which are inert under the conditions of the process may be employed. The amount'and nature of the solvent most suitable depends upon the components and the conditions of the process. In certain cases the solvent may be omitted entirely.

Acidic catalysts facilitate the reaction. Suitable acids include hydrochloric, hydrobromic, sulfuric, phosphoric, hydrofluoric, benzene sulfonic, and trichloracetic or other organic acids. In addition, acidic salts and acid-yielding substances such as boron trifiuoride, thionyl chloride, phosphorus chlorides and oxychlorides or sodi bisulfate are effective.

This invention afiords a simple, easy, and economical method whereby thioether derivatives of acid amides, including lactams, may be obtained in good yields.

These N-alkylthiomethyl derivatives of monobasic amides, including lactams, are useful as rubber chemicals, and petroleum within the scope of the claims.

What is claimed is: 1. An ether of an N-thiomethylamide of an open chain aliphatic monocarboxylic acid of at least four carbon atoms wherein the hydrogen of the mercapto group is replaced by a monovalent aliphatic hydrocarbon radical.

2. A compound-of the formula RCONHCH2-S R' wherein R is a monovalent aliphatic radical of at least three carbon atoms joined through car-,

bon to the remainder of the molecule and R is a monovalent aliphatic hydrocarbon radical.

3. An ether of an N-mercaptomethylamide of an open chain aliphatic monocarboxylic acid of at least four carbon atoms wherein the hydrogen of the mercapto group is replaced by a monovalent aliphatic hydrocarbon radical.

4. An N-(allgylthiomethyl) amide of an open chain aliphatic monocarboxylic acid of at least four carbon atoms.

5. An N-(alkylthiomethyDamide of a fatty acid.

6. N-ethylthiomethyllauramide.

7. Process for the manufacture of condensation products, which comprises reacting, in the presence of an acid, an aliphatic hydrocarbon mercaptan with an N-methylolamide of an open chain aliphatic monocarboxylic acid of at least four carbon atoms.

8. Process for the manufacture of condensation products, which comprises reacting, in the presence of an acid, an alkyl mercaptan with an N-methylolamide of an open chain aliphatic monocarboxylic acid of at least four carbon atoms.

9. Process for the manufacture of condensation products, which comprises reacting, in the presence of an acid, an aliphatic hydrocarbon mercaptanwith a methylolamide or a fatty acid.

10. Process for the manuiacture of condensation products, which comprises reacting, in the presence or an acid, an alkyl mercaptan with a methylolamide of a fatty acid.

11. Process for the manufacture of condensa tion products, which comprises reacting, in the tion products, which comprises reacting, in the presence or an acid, an alkyl mercaptan with an amide of a fatty acid in the presence of a formaldehyde generating agent.

' PAUL ROI-LAND AUSTIN.

CHARLES EDWARD FRANK. 

